"In just a few months since legalization, we've seen several deaths directly linked to legal marijuana use, children bringing pot-infused snacks to school and law enforcement in neighboring states reporting an increase in the seizure of marijuana traced back to Colorado," said Earll.

55 percent of voters said yes to Initiative 502. In King County, 63 percent of voters approved the pot legalization; by contrast in Adams County 61 percent voted no.

"Washington and Colorado stunned much of the world by voting in November 2012 to legalize marijuana for adults over 21, and to create state-licensed systems for growing, selling and taxing the pot," reported Gene Johnson of the AP.

"Businesses including Cannabis City, which will be the first and, for now, only recreational marijuana shop in Seattle, got word early Monday morning from the state that they were licensed marijuana dealers."

Thirty days after Initiative 502 passed, smoking cannabis became legal for adults, with the state also crafting a "drugged driving" law.

"Tuesday's vote also begins a yearlong process for the state Liquor Control Board to set rules for heavily taxed and regulated sales at state-licensed marijuana stores, which are estimated to raise $1.9 billion in new revenue over five years," reported The Seattle Times in 2012.

"Many legal experts expect the U.S. Justice Department, which remained silent during presidential-year politics, to push back and perhaps sue to block I-502 based on federal supremacy."

Tuesday saw the opening of at least three retail cannabis stores: Cannabis City Seattle, Top Shelf Cannabis in Bellingham and The Freedom Market in Kelso, according to NBC News.

This new era of pot for Washington will not come without its complications, as NBC noted that the state has "a huge backlog for licenses."

"There are only 18 license reviewers sifting through thousands of applications. The first approvals for growers didn't go out until March, which left at most two growing cycles to stock the shelves," reported NBC.

"That's created an inescapable shortage of product, and a growing population of desperate, irate business people. Some have already gone under as opening day was delayed again and again. Others are trying to sell or hold on long enough to break even."

Washington joins Colorado as being a place where cannabis is legal. While both states approved referenda in 2012, Colorado has been quicker in getting pot to customers.